The effective reference frame in perceptual judgments of motion direction

Aga-Oglu, Mehmet; Herzog, Michael H.; Öğmen, Haluk

doi:10.1016/j.visres.2014.12.009

Cited by 9 publications

(9 citation statements)

References 95 publications

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“…Previously, we have shown that the perceived motion of a target stimulus can be influenced by nearby motion of another object, and that this object need not be surrounding the target stimulus, as in the induced-motion paradigm (Agaoglu et al, 2015;Noory et al, 2015). In this study, we started off by replicating our previous findings that each local motion vector has a reference field associated with it, and this is manifested by increased illusory percepts of backward motion with decreasing distance to this moving reference frame.…”

Section: Discussionmentioning

confidence: 51%

“…The fields created by different motion vectors interact in order to determine a motion vector that will serve as the reference frame at a given point and time in space. Previously, we have demonstrated the field-like nature-that is, the distance-dependent influence-of motion-based reference frames in the perception of motion direction (Agaoglu, Herzog & Öğmen, 2015;Öğmen et al, 2013). This concept of distancedependent reference-frame determination is also consistent with earlier observations of relative motion.…”

Section: Reference-frame Metric Field (Rfmf) Theorymentioning

confidence: 92%

“…Stimuli and procedures Previously, we have used a variant of the induced motion paradigm to see how various reference frames influence the perception of motion (Agaoglu et al, 2015). We used a small white square (56 cd/m 2 ), similar to the stimuli used in that study, as the target on a black background (<0.5 cd/m 2 ; see Fig.…”

Section: Methodsmentioning

confidence: 99%

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Field-like interactions between motion-based reference frames

Aga-Oglu

Herzog

Öğmen

2015

Atten Percept Psychophys

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A reference frame is required to specify how motion is perceived. For example, the motion of part of an object is usually perceived relative to the motion of the object itself. Johansson (Psychological Research, 38, 379-393, 1976) proposed that the perceptual system carries out a vector decomposition, which rewsults in common and relative motion percepts. Because vector decomposition is an ill-posed problem, several studies have introduced constraints by means of which the number of solutions can be substantially reduced. Here, we have adopted an alternative approach and studied how, rather than why, a subset of solutions is selected by the visual system. We propose that each retinotopic motion vector creates a reference-frame field in the retinotopic space, and that the fields created by different motion vectors interact in order to determine a motion vector that will serve as the reference frame at a given point and time in space. To test this theory, we performed a set of psychophysical experiments. The field-like influence of motion-based reference frames was manifested by increased nonspatiotopic percepts of the backward motion of a target square with decreasing distance from a drifting grating. We then sought to determine whether these fieldlike effects of motion-based reference frames can also be extended to stationary landmarks. The results suggest that reference-field interactions occur only between motiongenerated fields. Finally, we investigated whether and how different reference fields interact with each other, and found that different reference-field interactions are nonlinear and depend on how the motion vectors are grouped. These findings are discussed from the perspective of the reference-frame metric field (RFMF) theory, according to which perceptual grouping operations play a central and essential role in determining the prevailing reference frames.

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Section: Discussionmentioning

confidence: 51%

Section: Reference-frame Metric Field (Rfmf) Theorymentioning

confidence: 92%

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Field-like interactions between motion-based reference frames

Aga-Oglu

Herzog

Öğmen

2015

Atten Percept Psychophys

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“…For example, the point lights placed on a person in the biological motion paradigm (Johansson, 1973) creates a very complex stimulus; however, by grouping these points into a meaningful Gestalt (Yantis, 1992), the visual system is capable of computing a common reference frame, which can be used to simplify the relative motions of various point lights. Several studies showed that when the stimulus allows grouping of parts, motion groupings based nonretinotopic reference frames (relative motion) account for perceived direction of motion (Agaoglu et al, 2015a(Agaoglu et al, , 2015bBoi, Öğmen, Krummenacher, Otto, & Herzog, 2009;Duncker, 1929Duncker, /1938Johansson, 1973;Noory et al, 2015). In fact, Agaoglu et al (2015b) quantified the contributions of retinotopic, spatiotopic, and relative-motion reference frames and showed that relative motion dominated both during fixation and SPEM, with a contribution more than 80% when the distance between the stimuli was 2 degrees.…”

Section: Discussionmentioning

confidence: 99%

“…Several studies showed that when the stimulus allows grouping of parts, motion groupings based nonretinotopic reference frames (relative motion) account for perceived direction of motion (Agaoglu et al, 2015a(Agaoglu et al, , 2015bBoi, Öğmen, Krummenacher, Otto, & Herzog, 2009;Duncker, 1929Duncker, /1938Johansson, 1973;Noory et al, 2015). In fact, Agaoglu et al (2015b) quantified the contributions of retinotopic, spatiotopic, and relative-motion reference frames and showed that relative motion dominated both during fixation and SPEM, with a contribution more than 80% when the distance between the stimuli was 2 degrees. The dominance of the relative motion decreased with the distance between stimuli; however, for separations as large as 11 deg, the contribution of relative motion was still substantial (60%).…”

Section: Discussionmentioning

confidence: 99%

The reference frame for encoding and retention of motion depends on stimulus set size

Huynh

Tripathy

Bedell

et al. 2017

Atten Percept Psychophys

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The goal of this study was to investigate the reference frames used in perceptual encoding and storage of visual motion information. In our experiments, observers viewed multiple moving objects and reported the direction of motion of a randomly selected item. Using a vector-decomposition technique, we computed performance during smooth pursuit with respect to a spatiotopic (nonretinotopic) and to a retinotopic component and compared them with performance during fixation, which served as the baseline. For the stimulus encoding stage, which precedes memory, we found that the reference frame depends on the stimulus set size. For a single moving target, the spatiotopic reference frame had the most significant contribution with some additional contribution from the retinotopic reference frame. When the number of items increased (Set Sizes 3 to 7), the spatiotopic reference frame was able to account for the performance. Finally, when the number of items became larger than 7, the distinction between reference frames vanished. We interpret this finding as a switch to a more abstract nonmetric encoding of motion direction. We found that the retinotopic reference frame was not used in memory. Taken together with other studies, our results suggest that, whereas a retinotopic reference frame may be employed for controlling eye movements, perception and memory use primarily nonretinotopic reference frames. Furthermore, the use of nonretinotopic reference frames appears to be capacity limited. In the case of complex stimuli, the visual system may use perceptual grouping in order to simplify the complexity of stimuli or resort to a nonmetric abstract coding of motion information.

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Spatial properties of non-retinotopic reference frames in human vision

2015

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Many visual attributes of a target stimulus are computed according to dynamic, non-retinotopic reference frames. For example, the motion trajectory of a reflector on a bicycle wheel is perceived as orbital, even though it is in fact cycloidal in retinal, as well as spatial coordinates. We cannot perceive the cycloidal motion because the linear motion of the bike is discounted for. In other words, the linear motion common to all bicycle components serves as a non-retinotopic reference frame, with respect to which the residual (orbital) motion of the reflector is computed. Very little is known about the underlying mechanisms involved in formation and operation of non-retinotopic reference frames. Here, we investigate spatial properties of non-retinotopic reference frames. We show that reference frames are not restricted within the boundaries of moving stimuli but extend over space. By using a variation of the Ternus-Pikler paradigm, we show that the spatial extent of a non-retinotopic reference frame is independent of the size of the inducing elements and the target position near the object boundary. While dynamic reference-frames interact with each other significantly, a static reference-frame has no effect on a dynamic one. The magnitude of interactions between two neighboring dynamic reference-frames increases as the distance between them reduces. Finally, our results indicate that the reference-frame strength is significantly attenuated if the locus of attention is shifted to the elements of the neighboring reference instead of the main reference. We suggest that these results can be conceptualized as reference frames that act and interact as fields.

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The effective reference frame in perceptual judgments of motion direction

Cited by 9 publications

References 95 publications

Field-like interactions between motion-based reference frames

Field-like interactions between motion-based reference frames

The reference frame for encoding and retention of motion depends on stimulus set size

Spatial properties of non-retinotopic reference frames in human vision

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